Step-by-step explanation:
According to pythagoras theorem the square length of hypotenuse is equal to sum of other two sides
n^2 + 19^2 = 15^2
n^2 + 361 = 225 if we subtract 361 from both sides
n^2 = -136 but the root of square cannot be negative
I believe there's a mistake in this question so you should ask your teacher.
